Map databases may be used to provide navigation based features such as routing instructions for an optimum route from an original location to a destination location and map based features such as section and display of maps to manually locate locations or points of interest. Map databases are used in driver assistance systems or driverless systems. Map databases are also used in systems that improve vehicle fuel economy, such as systems that optimize transmission gear selection taking into account upcoming slope and speed changes.
Map attributes often change over time. As new roads are built, other roads are closed, speed limits change, or locations of business are changed, the geographic database should be updated. Real world observations may be indicative of the map attribute changes. Crowd sourcing may be used to receive update information from users. The data may be unreliable in some circumstances. Challenges remain in evaluating crowdsourced data for updating map attributes.